The invention relates to a saw-tooth double-faced concave U sharp type concrete laser welding cutting disk preparation method and belongs to the technical field of diamond machining tools. The preparation method is implemented through the following working procedures that a metallic bond and diamond are subjected to material preparation, granulation, cold pressing, hot pressed sintering, laser welding, first edge forming, polishing, painting, checking packaging storage in sequence. According to the saw-tooth double-faced concave U sharp type concrete laser welding cutting disk preparation method, a diamond tool bit is formed by the procedures that the metallic bond and diamond are subjected to the hot pressed sintering under vacuum conditions. By means of the saw-tooth double-faced concave U sharp type concrete laser welding cutting disk preparation method, the prepared cutting disk has the advantages that the cutting seam is narrow, the consumable items are less, the cutting deflection is small, the cut edge is neat, the cutting sharpness is good, and the cutting disk is particularly suitable for the cutting of hard materials including building materials, wall bodies, cement concrete, solidified concrete, reinforced concrete, hard concrete bricks, concrete piles and the like.